1. Field of the Invention.
This invention pertains to the selective display of text data, particularly news-type data, which is received at a high rate and displayed at a low rate.
2. Description of the Prior Art
It is well-known in the prior art to provide a data feed including text data to broadcast news-type data. Advances in communications technology have allowed the data rate for such broadcasts to be very high. For instance, the Dow Jones.RTM. news service typically broadcasts at 9600 baud. Future advances in communications technology can certainly be expected to increase this rate even further.
However, display rates for such data are limited by the bounds of human perception and must be limited to the comprehension rate of a typical reader. This is particularly true for large-scale LED (light-emitting diode) displays, such as disclosed in U.S. Pat. No. 4,682,162, marketed by the assignee of the present application under the name DataJet.RTM.. A typical data communication rate as received by such a display is 300 baud.
As the news-data transmitted over a data feed is not continuous, that is, there are periods of high-speed transmission ("bursts") interspersed with periods of null or no transmission, the problem of the data transmission rates being higher than human comprehension rates can be alleviated by the use of a buffer. The buffer then stores the news-type data which eventually is sequentially displayed and subsequently discarded. However, this simple approach is not adequate during times of frequent news-type data transmission where the data buffer would simply overflow and data would be lost.
Moreover, such a simple buffering approach would lose data during times of frequent data transmission based substantially entirely upon the chronology of recent transmission and would not be able to distinguish between more important news stories and less important news stories.
Similarly, even during routine display within the capacity and capability of such a simple buffering system, no distinction is made between more important news stories and less important news stories, and more important news stories would wait until all previously transmitted less important news stories were sequentially displayed.